Water is called the universal solvent because it can dissolve more substances than any other liquid. This is primarily due to its polar molecular structure , where the oxygen atom has a slight negative charge and the hydrogen atoms have a slight positive charge. This polarity allows water to surround and break apart charged or polar molecules, effectively dissolving them. Additionally, water molecules form hydrogen bonds , which help trap and carry other particles. Water also has a high dielectric constant , meaning it can weaken the forces between charged particles and keep them dissolved. These properties make water excellent at dissolving salts, sugars, gases, and many other substances, though it does not dissolve non-polar substances like oils or fats. Water's remarkable dissolving ability is crucial for life, as it transports nutrients, gases, and minerals in bodies and ecosystems, and supports many chemical reactions in nature and biological systems. This combination of polarity, hydrogen bonding, and dielectric constant explains why water is known as the universal solvent. In summary, water's unique chemical and physical properties allow it to dissolve a wide variety of substances, earning it the title "universal solvent".